A second portal cannot be cooled as intensively by the flow shadow as a first portal. It is here that if the first portal to a cylinder is furnished with an injection nozzle that is completely cooled by a liquid jacket. By contrast, the second portal is provided with an ignition device, which is arranged parallel to the camshaft, and now exposed to an elevated temperature load in the flow shadow of the injection nozzle. An excess temperature of the ignition plug can lead to pre-inflammation and knocking in the combustion engine. This is unfavorable especially in charged engines, since the combustion chamber pressure and combustion chamber temperature are obviously correlated with the maximum torque.
High temperatures on the ignition plug increase the probability of a mechanical failure. In addition, the injection nozzle or injector is exposed to the extremely high temperatures of the combustion chamber in directly and centrally injecting internal combustion engines with a longitudinally perfused liquid cooling system. When the injector is in a central position, the temperature at the injector tip rises by up to approximately 15° C. compared with a lateral injector arrangement. This also increases the danger of harmful fuel deposits forming on the injection nozzle.
Known from publication U.S. Pat. No. 6,827,049 B2 is a water jacket with exhaust manifold outlet openings, which remove the exhaust gases of a cylinder. The water jacket exhibits an upper, central, and lower water pathway. The lower water pathway of the water jacket exhibits sealed off areas that force the coolant to flow through the central water pathway. As a result, this publication discloses that a coolant can be forced to cool thermally critical areas more intensively by taking suitable measures and shaping the water jacket.
At least one object is to create a cylinder head with a liquid cooling system in which cooling is improved in thermally critical areas. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.